Here's a related thread, although the solution hinted there is basically the same as what IOhannes already mentioned.
http://lists.puredata.info/pipermail/pd-list/2010-02/075936.html http://lists.puredata.info/pipermail/pd-list/2010-02/075936.html
I don't know why loadbangs don't bang on dynamic creation, but I solve it by having a receive for the bang instead. Create patch -> send bang to it.